The aim of the present study was to determine if leg function is associated with ventilatory efficiency during exercise in healthy older adults. 24 women and 18 men aged 60-80 years performed treadmill exercise to fatigue for calculation of ventilatory efficiency using the ratio of ventilation to carbon dioxide at the anaerobic threshold (VE/VCOAT). On a separate day, participants performed leg strength testing and graded single-leg knee extension exercise. The VE/VCOAT was higher in women than men (33±3 vs. 30±3; p=0.03). After adjustment for age and VO leg strength (knee extensor isometric force) was inversely associated with VE/VCOAT in women (r= 0.44, p=0.03) while no relationships were found for men. Strength-matched women and men had similar VE/VCOAT indicating that the correlation between leg strength and VE/VCOAT was strength- but not sex-specific. During knee extensor exercise, women with lower leg strength had increased VE/VCOslope across 0-15 W as compared to higher strength women (38±8 vs. 31±3; p<0.05), while no differences were found for men. These results find leg strength to be associated with ventilatory responses to exercise in healthy older women, a finding that might be related to lower leg strength in women than men.
- muscle strength
- sex differences